Sprinkler Valves

Control and regulate your sprinkler system with irrigation sprinkler valves

Sprinkler Valves - Sprinkler Valves

Sprinkler valves are an integral part of your irrigation system. They control and regulate the amount of water that each watering zone receives and may be controlled manually or electrically with a timer. Sprinkler valves also can be used to turn off your system in emergencies and prepare the system for winterization. This guide will discuss the different types of valves so you can pick the one best for you.

Valve Types

When installing a sprinkler system, you will install valves that control the flow of water, as well as emergency shut-off valves. Consider size, flow control and whether a valve “bleeds” internally or externally during installing.

Beyond valve issues, when installing a new irrigation system, you need to choose a method to prevent backflow, which can taint your drinking water. While anti-siphon valves have built-in backflow prevention (also called cross-connection control), you may need or want to install additional protection.

Local laws and regulations may dictate which types of valves and backflow preventers you can or cannot (or must) use, so be sure to consult them prior to installing your sprinkler system.

Anti-siphon valves

  • Helps keep drinking water safe
  • Have built-in backflow prevention
  • Easy to install
  • Manual or electric
  • Use where sprinkler lines are under land where chemicals are consistently used
  • Available in ¾- or 1-inch sizes
  • Install at least 6 inches above highest sprinkler head

Tip: Install electric valves with automatic timers for more convenient use. Manual valves can be retrofitted with an automatic valve adapter.

In-line valves

  • Usually installed below ground
  • No built-in backflow protection; typically used with a backflow preventer
  • Protected by valve boxes
  • Group of in-line control valves (known as a manifold) provides easy access and maintenance
  • Manual or electric
  • Varieties include angle and globe valves

Emergency shut-off valves

  • Cut the water supply to all or part of the system temporarily to prevent damage or to allow for maintenance and repair
  • They may be either gate or ball valves

Drain valves

  • Located at low points on the main and lateral lines
  • Used to drain water from the system to make repairs or for winterization in colder climates

Additional Valves

  • Gate valves are economical and require multiple turns to turn off water.
  • Ball valves require only a quarter turn and provide durability for frequent use.
  • Disk and butterfly valves are other types of high-performance emergency valves.
  • Indexing valves may be required in some areas.

Valve Considerations

  • Deciding how large a valve should be depends on your system’s flow rate. ¾-inch valves are ideal for most residential applications where the flow rate is around 8-10 gpm (gallons per minute). If the flow rate exceeds 15 gpm, you should use a 1-inch valve.
  • Installing flow control will allow you to customize performance by ensuring that the right amount of water is used in each zone. If valves are activated manually, they may be done so using the manual bleed feature.
  • Valve diameter does not necessarily need to match pipe diameter.
  • Flow control helps conserve water by preventing fogging and misting.
  • External bleed valves are ideal for flushing dirt from lines during installation and repairs.
  • Internal bleed valves vent water to the downstream side to prevent water from leaking.

Backflow Preventers & Other Features

When sprinkler heads operate, they sometimes create a vacuum that can cause water that has already been expelled to be sucked back in. This water, which may have picked up chemicals from pesticides, fertilizers and other lawn products, can filter back into your drinking water and cause illness.

Backflow may be caused by pressure generated by equipment (pressure backflow) or pressure exerted upon water (back siphonage). Backflow preventers stop this from happening and, in many cases, are required by local codes and regulations.

Atmospheric Vacuum Breaker (AVB)

  • Opens a vent that allows air into the system to prevent siphoning
  • Installs between the circuit valve and delivery device
  • Most economical
  • Must be installed above ground
  • One AVB must be installed for each control valve

Double Check Backflow Preventer

  • Uses two spring-loaded, independently operating check valves to block backflow if water pressure temporarily drops
  • Prevents back siphonage
  • May be required in some areas
  • May be installed underground
  • Protects against pollutants but may not protect against contaminants

Pressure Vacuum Breaker (PVB)

  • Installs on the pressure side of emergency shutoff valve to prevent back siphonage
  • Must be install prior to installing valves
  • May not be suitable for drip irrigation systems
  • Local regulations may prevent usage

Reduced Pressure Backflow Preventer (RP)

  • Features two check valves and a pressure differential relief valve that operates automatically
  • Installs between two emergency shutoff valves
  • Prevents back siphonage and pressure backflow
  • Requires larger upfront investment
  • Highly effective and efficient
  • Must be installed above ground

Optional Features:

Built-In Pressure Regulators: Valves with pressure regulators control the pressure level directly, rather than relying on a system regulator that may be too far away to effectively regulate pressure at far ends of the line.

Molded Bolt: Valves with the stud part of a bolt molded to their bodies will not fall off when removing the nut, meaning you won’t accidentally lose it in the wet, muddy ground nearby.

Internal Scrubbers: If you draw water from a pond or irrigation ditch, look for valves with scrubbers that automatically remove algae to prevent buildup from blocking the opening.